The state board of equalization shall equalize the values placed upon property subject to valuation. Representatives of the board of university and school lands may appear before the state board of equalization to oppose unreasonable or unjust valuations placed upon property subject to valuation as equalized by the county board of equalization, or to oppose any change in valuations as proposed by the state board of equalization, to the end that all valuations of property subject to valuation may be uniform with valuations of comparable property throughout the state.